942 THE RECENT BIRD TRACKS 
of the Connecticut River beds, there were volcanic dis- 
turbances, attended by the formation of dykes, and the 
spreading out over the beds of thick masses of lava. The 
New-Red Sandstone period was attended in Nova Scotia by 
similar phenomena. Just after the formation of the sand- 
stone beds in the Basin of Minas and Bay of Fundy, sub- 
marine volcanic action broke out along the line of the 
present North Mountains, and immense quantities of 
melted matter were thrown up from beneath, and spread 
over the New-Red Sandstone strata, either in liquid, mol- 
ten streams, or a volcanic ash. This ancient lava is called 
trap. The volcanic disturbance went on for some time, 
until’ these beds had acquired a great thickness. Similar 
eruptions took place at the same time at the Two, Five, 
and Partridge Islands, Capes d’Or and Sharpe, and at the 
Isle Haute. It is very probable that all these now iso- 
lated trap masses may have been at that time continuous. 
The land was then elevated so as to bring all their beds 
in the Basin of Minas, and along the shores of the Bay of 
Fundy above water, and as the red sandstone beds had a 
slight dip to the northward along the southern coast, the 
volcanic beds had a like dip towards and under the bay. 
The trap beds were very thin inland, but became thicker 
towards the shore. Running water began its work on the 
southern edge of the trap deposit, along the present line 
of the valley between the North and South Mountains, 
and with the assistance of glacial action and the sea, 
_ which afterward flowed through it, excavated that depres- 
sion. To the north, the waves, beating along the whole 
bay coast for centuries, cut away the trap-beds, so that 
we have now only a narrow strip left, the North Moun- 
tains from Blomidon to Briar Island. At the time of the 
elevation of the New-Red Sandstone beds, the Basin of 
